What is not allowed in a command economy?

Command economy can be define as an economy in which production, investment, prices, and incomes are determined by a government.Central government is responsible for all this.No other authorities are allowed to fix any of the above mentioned categories.
All goods and services production is set through the central plan.

It is evolution, because we all have some of the same traits like eye color or shape or ears.

A. convection currents in the mantle.is the correct answer